1. Field of the Invention
The present invention relates to an adjustable book holder, and more particularly to an adjustable book holder having one or more auxiliary frames to be selectively and optionally coupled thereto for increasingly holding more books or the like.
2. Description of the Prior Art
Various kinds of typical adjustable book holders have been developed to hold various amount of books therein, and normally comprise two shelf members slidably and adjustably secured together, to support different amount of books.
For example, U.S. Pat. No. 1,682,060 to Banks discloses one of the typical adjustable book holders comprising two shelf members slidably and adjustably secured together. However, the shelf members may not be solidly secured together.
U.S. Pat. No. 2,545,844 to Cougias discloses another typical adjustable book holder also comprising two shelf members slidably and adjustably secured together, and biased or forced toward each other with spring members. Similarly, the shelf members also may not be solidly secured together.
U.S. Pat. No. 2,527,277 to Schade discloses a further typical adjustable book holder comprising one or more plates slidably engaged onto or along two tracks or a tray, to allow different amount of books to be attached onto and supported on the tracks of the tray. Similarly, the plates also may not be solidly secured together.
U.S. Pat. No. 3,760,744 to Cruckshank discloses a still further typical adjustable book holder also comprising two shelf members slidably and adjustably secured together, and legs secured to the shelf members respectively. The legs may be engaged with the shelf members to limit the movement of the shelf members relative to the legs. However, similarly, the shelf members also may not be solidly secured together.
U.S. Pat. No. 4,066,168 to O'Toole et al. discloses a still further typical adjustable book holder comprising two connecting sections each having two arms optionally and adjustably secured to holes of a plate, to adjustably secure and retain and support different amount of books on the plate. However, the connecting sections include a weak structure that may not be used to stably support the books on the plate.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional adjustable book holders.